Modified infratemporal fossa approach via lateral transantral maxillotomy: a microsurgical model

Skull Base

Modified Infratemporal Fossa Approach via Lateral Transantral Maxillotomy: A Microsurgical Model Ibrahim Sabit, M.D.,* Steven D. Schaefer, M.D.,† and William T. Couldwell, M.D., Ph.D.* *Department of Neurosurgery, New York Medical College, Valhalla, New York, and †Department of Otolaryngology, New York Eye and Ear Infirmary, New York Medical College, New York, New York

Sabit I, Schaefer SD, Couldwell WT. Modified infratemporal fossa approach via lateral transantral maxillotomy: a microsurgical model. Surg Neurol 2002;58;21–31.

rimal apparatus and all branches of the facial nerve. In addition, the reflected pterygoid muscle can be used as a vascularized flap for closure of the skull base defect.

BACKGROUND

CONCLUSION

Lateral approaches have traditionally been used to gain access to lesions of the infratemporal fossa (ITF). However, dysfunction of the facial nerve secondary to its translocation, conductive hearing loss, and dental malocclusion because of mandibular head resection or dislocation are significant limitations associated with some of these approaches. Although facial nerve translocation and extended maxillotomy approaches avoid some of these drawbacks, they are invasive and require extensive osteotomies and facial incisions. To avoid these potential complications and maintain an extranasal/extraoral exposure, we studied the use of a lateral and posterior extension of an anterior transmaxillary approach to the cavernous sinus.

The approach may be an alternative less invasive approach to the ITF and may be suitable for ITF lesions that have minimal lateral or intracranial extension. © 2002 by Elsevier Science Inc.

METHODS

The study was performed on 12 cadaver specimens and two dry skulls. An initial nasolabial fold incision, followed by an en bloc osteotomy of the anterior and lateral maxilla provides a window into the medial ITF. After osteotomy of the pterygoid plate and the posterior maxillary wall, the floor of the middle fossa is exposed to reveal the mandibular and maxillary divisions of the trigeminal nerve exiting their respective foramina. The floor of the middle fossa is then drilled postero-medial to the foramen ovale to gain access to the course of the C3-C4 portion of the petrous carotid artery and the eustachian tube. The upper two-thirds of the clivus and the pituitary gland are accessed after drilling of the floor of the sella turcica and form the posterior limit of this exposure. RESULTS

The technique offers a trajectory to the medial ITF and skull base that does not necessitate palatal splitting or opening of the nasopharynx. The anterior route avoids temporomandibular joint disruption, and spares the lacAddress reprint requests to: Dr William T. Couldwell, Department of Neurosurgery, The University of Utah, Suite 3B409, 30 North 1900 East, Salt Lake City, UT 84132. Received August 6, 2001; accepted February 7, 2002. © 2002 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010

KEY WORDS

Carotid artery, infratemporal fossa, maxillary sinus, minimally invasive surgery.

ifferent combinations of lateral approaches have been the mainstays of surgical management for lesions of the infratemporal fossa (ITF). Classically, the approaches described by Fisch, alone or in combination with subtemporal/infratemporal approaches, have yielded good access to the region of the temporal bone and ITF [10,11,28,29]. However, facial nerve trauma secondary to its translocation if performed, conductive hearing loss, and mandibular malocclusion due to disarticulation of the temporomandibular joint remain significant drawbacks to these approaches. The facial translocation approach provides a wide exposure for pathology of the nasopharynx, clivus, lateral cranial base, and ITF secondarily [13,17–19,31,32]. It is easily combined with other lateral or anterior approaches to gain access to the petrous apex and cavernous sinus. The approach, however, is quite invasive and associated with significant cosmetic deformity, with possible transection of the frontalis branch of the facial nerve, the infraorbital nerve, and the nasolacrimal duct. The same areas are also accessible via an anterior subtotal maxillectomy/ extended maxillotomy with better cosmetic out-

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come [6,7]. Although providing good access to the medial cranial base, the approach requires palatal splitting and extensive facial osteotomies. Modest lateral access to intracranial pathology limits the usefulness of this approach; for lesions limited to the ITF, subjecting patients to such invasive approaches may not be warranted. Previous work from our laboratory has focused on examining a less invasive transmaxillary approach to the skull base. We studied the direct route afforded by a limited transmaxillary approach to the ipsilateral anterior cavernous sinus [9]. A modification of that straight anterior trajectory to include a transsphenoidal approach afforded better access to the infrahypophyseal region and the cavernous sinus from below [27,30]. We now examine the lateral and posterior extension of a minimally invasive transmaxillary approach that would avoid the complications associated with the complex transfacial and lateral approaches to access lesions of the ITF with limited extension to the skull base.

Materials and Methods The dissections were carried out on 12 freshly embalmed cadaveric specimens and two dried bone specimens. Microsurgical techniques and metric measurements were conducted with a Zeiss OPMI 1 FC (Carl Zeiss, Oberkochen, Germany) and documented with a Nikon FE camera with Kodak Ektachrome 160 film. A Midas Rex 3 drill was used for all bone drilling (Midas Rex, Fort Worth, TX, USA).

Results ANATOMY OF THE INFRATEMPORAL FOSSA The ITF lies posterior to the maxilla and beneath the floor of the middle fossa. Its osseous landmarks are limited anteriorly by the posterior surface of the maxilla (Figure 1C). The inferior aspect of the greater wing of the sphenoid bone through which the foramen spinosum, foramen rotundum, and foramen ovale transmit the middle meningeal artery, maxillary nerve (V2), and the mandibular nerve (V3), respectively, forms the superior border of the ITF. Superiorly and laterally, the ITF is separated from the temporal fossa by the infratemporal crest and merges with the belly of the temporalis muscle. Its medial border is formed by the lateral pterygoid plate anteriorly, and the medial pterygoid muscle and the tensor veli palatini muscle more posteriorly. Lying between the anterior and medial bor-

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ders of the ITF is the pterygomaxillary fissure, which allows for communication between the ITF and the pterygopalatine fossa leading to the nasopharynx. The pterygopalatine fossa in turn is formed by the posterior part of the maxilla and the anterior segment of the lateral pterygoid plate and contains V2, the sphenopalatine ganglion, and the sphenopalatine artery, which is the terminal branch of the internal maxillary artery that courses medially toward the nasopharynx. Posteriorly, the ITF extends to the glenoid fossa and the temporomandibular joint. There is no inferior border to the ITF. A thorough understanding of the musculature of the ITF is critical and is an essential part of the surgical anatomy of this complex region. The lateral pterygoid muscle composes the bulk of the musculature of the ITF. It arises from the neck of the mandible laterally, coursing horizontally inferiorly to the middle cranial fossa. The muscle has two medial heads, the infratemporal head that inserts on the lateral aspect of the greater sphenoid wing, and a pterygoid head that inserts on the lateral pterygoid plate (Figure 2). In the medial compartment of the ITF, the medial pterygoid muscle lies deep to the medial attachment of the lateral pterygoid muscle on the lateral pterygoid plate. The muscle arises from the medial aspect of the lateral pterygoid plate, coursing inferomedially to insert on the ramus and the angle of the mandible medially. The sphenopalatine artery usually passes anterior to the muscle fibers as it courses toward the sphenopalatine fossa. Just deep to the medial pterygoid muscle is the levator veli palatini muscle. The muscle has a characteristic pyramid shape, lies superficial to the cartilaginous portion of the eustachian tube, and courses inferiorly to insert on the soft palate. The levator veli palatini muscle lies posteromedial to the tensor veli palatini and courses almost parallel to the inferior surface of the cartilaginous part of the auditory tube to also insert on the soft palate. The neurovascular structures of the ITF are illustrated below in the description of the proposed approach. The surgical anatomy of the ITF is described thoroughly in two excellent reviews [3,34]. SURGICAL APPROACH The objective of this approach is to maximize cosmesis and obtain an adequate anterolateral trajectory to the ITF and floor of the middle cranial fossa. The head is placed in a supine position, extended 15 degrees, and rotated 20 degrees to the contralateral side of the ITF targeted. A nasolabial fold incision is performed from just inferior to the lacrimal canaliculi and extending along the sulcus inferiorly to the

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C (A and B) Artist’s impression of the initial nasolabial fold incision and maxillotomy. The incision runs in a natural crease and thus offers excellent cosmetic outcome. The incision is limited superiorly by the lacrimal canaliculi and terminates inferiorly at the level of the upper lip, where the buccal branch of the facial nerve courses to innervate the orbicularis oris muscle. With the cheek retracted, a wide lateral exposure of the maxilla to zygomaxillary suture is established. The infraorbital nerve and artery are retracted intact with the cheek flap superiorly. (C) Dry bone specimen displaying the bony landmarks of the right infratemporal fossa and an outline of the maxillotomy. FO ⫽ foramen ovale, iof ⫽ infraorbital foramen.

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Schematic illustrations of cross-sections of the stages of the ITF exposure by the lateral maxillotomy route. An en-bloc osteotomy of the anterolateral wall of the maxilla is carried out with a fine oscillating saw. The posterior wall of the maxilla is drilled to gain access to the medial ITF and pterygopalatine fossa. Top left: Macro view of the operative window gained by removal of the anterior and posterior walls of the maxilla to gain access to the medial ITF and pterygopalatine fossa. The dissection extends from the posterior limit of the maxilla to the level of the cartilaginous portion of the auditory tube posteriorly. Top right: Sagittal view of the ITF and medial cranial base with sequential stages of the dissections labeled in the coronal plane. The shaded area corresponds to the anterior view in the previous figure. 2: With the lateral wall of the maxilla removed. 3: Magnified view of the area in the dotted circle in 2 after the pterygoid venous plexus has been dissected. This offers clear visualization of the anterolateral and posteromedial trunks of V3 in the ITF. 4: With the neurovascular components of the ITF clearly identified, the dissection is extended medially by drilling the medial pterygoid plate to reveal the attachment of the underlying medial pterygoid muscle. 5: The medial pterygoid muscle is cut at its medial attachment and reflected inferiorly intact with its vascular supply. The levator muscles and the Eustacian tube lie in the plane immediately deep to the medial pterygoid muscle in the medial posterior ITF. a ⫽ artery; m ⫽ muscle; n ⫽ nerve.

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The lateral wall of the maxillary sinus is opened, and the mucosa is removed to reveal the inferior temporalis fibers coursing toward their inferior attachment on the medial aspect of the angle of the mandible. The internal maxillary artery (IMA) divides into its terminal branch, the sphenopalatine artery (SPA), in the pterygopalatine fossa, which lies posterior to the maxilla. The two heads of the lateral pterygoid muscle occupy most of the ITF and lie posterior to the IMA. V2 ⫽ maxillary nerve, PSAN ⫽ posterior superior alveolar branch of V2. PH and ITH ⫽ pterygoid and infratemporal head of lateral pterygoid muscle, respectively.

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level of the upper lip (Figures 1A and B). The buccal branch of cranial nerve VII (which courses inferomedially in the face and innervates the muscle fibers of the orbicularis oris at the inferior-most aspect of the nasolabial sulcus) is spared by this incision. Inferiorly, this incision is just superior to the upper border of the orbicularis oris. The skin is then retracted to expose the maxilla and the intact

infraorbital nerve and artery (Figure 1C). The large exposure offered by this incision allows for an enbloc maxillotomy of the anterior and lateral wall of the maxilla with a micro-oscillating saw. The anterior maxillary wall is removed as a unit and later replaced with titanium miniplates. The osteotomy outlined runs along the infraorbital margin superiorly and should bisect the infraorbital foramen.

After the pterygopalatine fossa is exposed, the lateral pterygoid muscle is transected at both medial attachments, and the superior aspect of the lateral pterygoid plate is drilled to access the main trunk of the mandibular nerve (V3) exiting the foramen ovale. The buccal and temporalis (motor) branches of V3 are visualized. Superiorly and anteriorly, the maxillary nerve (V2) is also seen exiting the foramen rotundum at the base of the lesser wing of the sphenoid bone. (Artist’s depiction in Figure 2 (2).) br ⫽ branch; n ⫽ nerve.

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The pterygoid venous plexus is dissected and the microdissection extended laterally to offer access to the neurovascular components of the anterolateral ITF. The components of the anteromedial (lingual nerve [lingual n] and posterior alveolar nerve [post alv n]) and posterolateral (buccal nerve [pictured here] and temporalis nerve [out of view]) trunk of V3 are visualized. The middle meningeal artery (mma) is seen arising from the internal maxillary artery and entering the base of the skull at the foramen spinosum lateral and posterior to V3. The accessory middle meningeal artery also arises from the internal maxillary and enters the IC compartment through the foramen ovale. The auriculotemporal nerve (auriculotemp n) wraps around the mma as it courses laterally to innervate the parotid gland. (Artist’s depiction in Figure 2 (3).)

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This permits further lateral mobilization of the infraorbital nerve, which can be transposed intact with the cheek flap to gain a more extended lateral access to the ITF. For small lesions of the ITF targeted by the approach, a sublabial incision can be performed to avoid facial incisions, as previously described [9]. The technical aspects of the approach are illustrated diagrammatically in Figure 2. After the osteotomy of the anterolateral maxilla, the mucosa of the maxillary sinus is removed, and the lateral and posterior walls are drilled. The trajectory obtained by this osteotomy provides a direct access to the medial aspect of the ITF. With the sinus opened, a clear view of the anterior musculature of the ITF is provided (Figure 3). The masseter muscle is retracted laterally with fishhooks and included with the cheek flap. The temporalis muscle fibers are seen as they course medial to the coronoid process of the mandible toward their inferior attachment at the angle of the mandible. The internal maxillary artery courses horizontally and gives rise to the sphenopalatine artery in the pterygopalatine fossa. The maxillary nerve (V2) exiting the foramen rotundum and coursing in the pterygomaxillary space toward the roof of the maxillary sinus, the posterior superior alveolar branch of V2, the pterygoid and infratemporal heads of the lateral pterygoid muscle are also clearly identified.

The lateral pterygoid muscle occupies the bulk of the ITF and its removal is essential to obtain access to deeper structures. After the two medial heads of the lateral pterygoid muscle are transected and reflected laterally, the lateral pterygoid plate is thinned with a high-speed drill to allow visualization of the neurovascular structures of the medial ITF and pterygopalatine fossa (Figure 4). Clear visualization of the mandibular division of the trigeminal nerve (V3) exiting the foramen ovale (which lies only 5 to 7 mm posterolateral to the pterygoid plates) is obtained. The pterygoid venous plexus surrounds V3 between the lateral pterygoid muscle and the medial pterygoid muscle. It predominantly drains into the maxillary vein but also has communications with the cavernous sinus posteriorly, and with smaller venous channels at the foramen ovale, foramen spinosum, and foramen lacerum. Intraoperatively, the pterygoid venous plexus is a potential source of bleeding and must be controlled before further dissection can be safely performed. With the pterygoid venous plexus dissected out of the field, the main neurovascular components of the ITF come into full view (Figure 5). The internal maxillary artery is identified at the origin of the middle meningeal artery (seen entering the foramen spinosum), with the accessory middle meningeal artery passing through the foramen ovale intracranially. The main components of both the anterolat-

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(A) The pterygoid plates are drilled and the medial pterygoid muscle cut from its superior attachment and reflected inferiorly to reveal the musculature of the palate. The fan-shaped tensor veli palatini muscle lies immediately deep to the medial pterygoid muscle. The foramen ovale (fo) has been enlarged to provide complete access to V3 at the floor of the middle fossa. (Artist’s depiction in Figure 2 (5).) (B) Bony dissection showing the enlarged foramen ovale and the bony landmarks encountered at this stage. fr ⫽ foramen rotundum.

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eral and posteromedial trunks of V3 are clearly identified. The masseteric nerve (largest component of the anterolateral trunk) courses horizontally to innervate the masseter muscle. The buccal nerve (only sensory branch of the anterolateral trunk) is also identified in its downward course to the skin of the cheek. The large posteromedial trunk has three main components: the auriculotemporal nerve, the lingual nerve, and the inferior alveolar nerve. Unlike the other two inferiorly oriented branches, the auriculotemporal nerve courses posterolaterally and loops around the middle meningeal artery to its target areas in the parotid gland and temporal cutaneous tissue and external acoustic meatus. It contains both sensory and parasym-

pathetic postganglionic motor fibers from the otic ganglion that arose from the lesser superficial petrosal nerve. To expand the medial reach into the ITF, the medial pterygoid plate is drilled to expose the most medial musculature of the ITF and muscles to the palate (Figure 6A). Immediately deep to the medial pterygoid plate, the superior attachment of the medial pterygoid muscle is sharply divided and retracted inferiorly and can be used at the end of the procedure to provide a vascularized flap for reconstruction of the skull base defect. After the muscle is transected, the floor of the middle cranial fossa is thinned and the foramen ovale enlarged to facilitate the dissection (bony opening demonstrated in Fig-

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The tensor veli palatini muscle is cut at its attachment anteromedial to the auditory tube (aud tube) and reflected inferiorly to enhance medial access to the floor of the middle cranial fossa. The intact cartilaginous portion (cartl) of the auditory tube and the levator veli palatini muscle are seen medial to the main trunk of V3 at the enlarged foramen ovale.

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ure 6B). Just deep to the medial pterygoid muscle and anterior to the cartilaginous portion of the eustachian tube lies the thin fan-shaped tensor veli palatini muscle. The levator veli palatini lies medial and posterior to the tensor (Figure 7). It courses parallel to and immediately inferior to the eustachian tube to insert on the soft palate. At this stage in the dissection, the whole medial compartment of the deep ITF is accessed with clear identification of the major components. The exposure has a lateral reach that extends to the level of the superior insertion of the sphenomandibular ligament (Figure 2 (5)). With the floor of the middle cranial fossa drilled to expose the dura, intracranial extension of the dissection is made possible by careful tissue retraction and fine drilling. After the bone around the foramen ovale and foramen spinosum is drilled, the main trunk of V3 is retracted laterally to reveal the entire cartilaginous portion of the intact Eustachian tube. Further drilling with a 2-mm diamond burr medial to the main trunk of V3 and superior to the Eustachian tube provides a straight trajectory to the C4-C3 portion of the petrous carotid artery that lies immediately posterior to V3 at the foramen ovale (Figure 8). After the carotid artery is clearly identified, the inferior floor of the ipsilateral sella turcica is removed with a drill and microdissection technique. The drilling is extended posteriorly to the clivus and superiorly to the level of the posterior clinoid process bilaterally. At the conclusion of the dissection, the C3-C2 junction of the ICA is clearly identified entering the posterior cavernous

sinus, as is the entire pituitary gland, and the upper two-thirds of the clivus (Figure 9).

Discussion LATERAL APPROACHES TO THE ITF Lesions arising in the ITF have traditionally been accessed by a variety of approaches depending on size, location, and extent of intracranial extension. Large tumors such as juvenile nasopharyngeal angiofibromas and trigeminal (V3) schwannomas of the ITF and pterygopalatine fossa are usually excised with lateral approaches including the Fisch type C [10,11]. Although the lateral approaches provide excellent visualization of the ITF structures and good control of the petrous ICA, they have serious limitations that include conductive hearing loss due to the sacrifice of the middle ear apparatus (Fisch types A, B, and C). Dental malocclusion secondary to the disarticulation of the mandible is another complication associated with those procedures. Furthermore, the facial nerve traverses the field of view in the lateral approaches proposed by Fisch, and its dissection or manipulation is required to gain access to the region. The Fisch type D infratemporal preauricular approach preserves hearing and decreases the potential for damage to the facial nerve, but provides limited access to pathology of the ITF. The subtemporal/infratemporal approach proposed by Sekhar et al [28,29] is a modification of the Fisch approach to minimize facial nerve injury

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Using a 2-mm diamond burr, careful drilling medial to V3 and superior to the intact auditory tube (aud tube) expands the exposure to gain access to the medial base of the skull and provides a direct route to the internal carotid artery (ICA) at the C3 portion. The motor root of V3 is seen lateral to the ICA.

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and avoid hearing loss. Von Doersten et al [33] reported a postoperative House Brackman facial nerve score range of 1.67 to 3.04 for lateral skull base approaches. ANTERIOR APPROACHES TO THE ITF Experience with anterior approaches to the midline pathology and the ITF secondarily have been reported extensively [1,2,4 – 8,12,15,16,20 –25,32,36]. Of these anterior approaches, access to the ITF is most afforded by the extended maxillotomy/maxillectomy and the facial translocation approach [6,7, 16 –19]. Hitotsumatsu et al [14] recently reviewed the surgical anatomy of both approaches and their combination with other approaches to access lesions of the skull base. The facial translocation approach provides the most unhindered access to the anterior and middle cranial base, the ITF, nasopharynx, and clivus. It is perhaps best described as an anterolateral approach that extends medially to include the maxillary sinus and nasopharynx. Unfortunately, this approach carries the risk of facial deformity, transection of the temporalis muscle, the frontalis branch of the facial nerve, and the infraorbital nerve. In addition, reconstruction of the lacrimal system may be required. The extended maxillotomy/subtotal maxillectomy is a midline approach to the skull base and cervical spine with secondary access to the ITF. It requires splitting of the palate and in effect is an extended transoral exposure [6,7]. In the facial translocation and extended maxillotomy, meningitis (if the dura is opened) and possible infective

The C3 portion of the ICA is identified after drilling the sphenoid bone in the posterior superior limit of the ITF. With the ICA clearly identified, the dissection can be safely extended to provide more superomedial access to the skull base. The floor of the sella is drilled to follow the course of the ICA as it enters the posterior cavernous sinus. The approach also allows access to the upper two-thirds of the clivus as well as the entire pituitary gland. The clivus has been partially drilled in this dissection at the upper one-third portion to show the dura of the posterior cranial fossa.

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arteritis are postoperative concerns due to the violation of the nasal and/or oral cavities. MODIFIED ANTERIOR APPROACH TO THE ITF The modified anterior ITF approach as proposed is an alternate, less invasive anterior route to the ITF that avoids the morbidity associated with the lateral approaches. This approach yields access to the ITF similar to that provided by the Fisch type D approach while avoiding the temporomandibular joint. The temporalis muscle, as well as all the branches of the facial nerve are avoided with this anterior route. The osteotomy of the maxilla performed above the alveolar process of the maxilla is designed to minimize dental injury by avoiding the neurovascular supply [35]. Similarly, including the infraorbital foramen in the maxillotomy and reflecting the intact neurovascular bundle superiorly with the cheek flap spares the infraorbital nerve and artery. The bone window at the end of the procedure can be closed with titanium mesh in a cosmetically acceptable fashion. At the conclusion of the dissection the ITF is exposed from the sphenomandibular ligament laterally to the sphenopalatine fossa medially. The extracranial course of V2 is visualized, as well as the course of V3 from the inferolateral wall of the cavernous sinus to its division into the anteromedial and posterolateral trunks in the ITF. At the cranial base, the complete intact cartilaginous portion of the eustachian tube, the C4 to C2 segments of the ICA, the entire pituitary gland, and the upper two-thirds of the clivus are exposed by this anterior route. Within the ITF, the approach offers visualization of all the vital neurovascular structures. Distance to the main trunk of V3 is reduced compared to the lateral approaches (4.1 cm vs. 3.7 cm to the foramen ovale). Posteriorly, the technique yields an extradural approach to the sellar region and upper clivus. An additional potential advantage of this approach would be the utilization of the transected pterygoid muscles at the conclusion of the procedure to provide a richly vascularized flap for reconstruction of the defect in the skull base. Potential complications from this procedure include bleeding from the pterygoid venous plexus and the internal maxillary artery. The internal maxillary artery is routinely embolized preoperatively in various head and neck surgical procedures to control bleeding; this is performed without complication as this facial region has extensive vascular anastomoses. The modified infratemporal fossa approach is potentially useful for lesions arising primarily in the

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anteromedial ITF compartment, and it avoids the morbidity of the lateral approaches to the ITF. For lesions limited to this area, it provides a direct approach and is a cosmetically superior alternative to more invasive anterior approaches. An overview of this approach was presented at the Tenth Annual Meeting of the North American Skull Base Society, May 29, 1999, Chicago, IL. ACKNOWLEDGEMENT The superb editorial assistance of Ms. Arlene Stolper Simon is greatfully acknowledged.

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COMMENTARY

The authors have presented here an excellent anatomical cadaveric study for addressing a surgical approach to the infratemporal fossa. The more typical lateral approaches have their problems and the authors have addressed those quite nicely. The apparent advantage of this approach is that by staying more midline, one avoids the morbidity associated with trauma to the facial nerve, articulation problems with the condyle, and other problems. This transmaxillary approach is used by our maxillofacial and ENT colleagues for exposures of tumors and dealing with fractures in this area. On our service, a joint exposure is done with the maxillofacial team doing the opening and exposure and the neurosurgeons then resecting the tumor or whatever abnormality is being addressed. As the authors have pointed out, the anatomy is not that difficult and the trajectory is a good one for the infratemporal region. One can also provide an exposure of the lateral sella and clivus with this technique. In our personal experience, this approach has been used for a clival chordoma and a large neurofibroma of the V3 and one rare myofibroblastic tumor in a child. If the surgeon carefully reviews and understands the anatomy and the approach, there are definitely certain cases in which this exposure will prove to be most helpful and also potentially reduce the morbidity to the patient. James T. Goodrich, M.D., Ph.D. Division of Pediatric Neurosurgery Montefiore Medical Center Bronx, New York

he time is always right to do what is right. —Martin Luther King, Jr.